vec2d examples converted

Author: monkstone

processing_app/library/vecmath/vec2d/README.txt

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+The particle_system_pshape.rb needs to be run with the --nojruby flag.
+The smoke_particle_system.rb needs to be run with the --nojruby flag.

processing_app/library/vecmath/vec2d/Rakefile

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+# Simple demo Rakefile to autorun samples in current directory
+# adjust path to rp5 executable, and or opts as required
+
+SAMPLES_DIR = './'
+
+desc 'run demo'
+task default: [:demo]
+
+desc 'demo'
+task :demo do
+  samples_list.shuffle.each{ |sample| run_sample sample }
+end
+
+def samples_list
+  files = []
+  Dir.chdir(SAMPLES_DIR)
+  Dir.glob('*.rb').each do |file|
+    files << File.join(SAMPLES_DIR, file)
+  end
+  return files
+end
+
+def run_sample(sample_name)
+  puts "Running #{sample_name}...quit to run next sample"
+  open("|jruby #{sample_name}", 'r') do |io|
+    while l = io.gets
+      puts(l.chop)
+    end
+  end
+end

processing_app/library/vecmath/vec2d/aabb_test.rb

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+#!/usr/bin/env jruby -v -W2
+# frozen_string_literal: true
+require 'propane'
+java_import 'monkstone.vecmath.AppRender'
+# Click on the box and drag it across the screen.
+class AaBbExample < Propane::App
+  attr_reader :block, :block_locked, :over_block, :bounds
+  BLOCK_WIDTH = 150
+  
+  def setup
+    sketch_title 'AaBb Example'
+    # on_top
+    @block = Block.new(
+      center: Vec2D.new(width / 2, height / 2),
+      size: Vec2D.new(BLOCK_WIDTH, BLOCK_WIDTH))
+    @locked = false
+    @over_block = false
+    @bounds = AaBb.new(
+      center: Vec2D.new(width / 2, height / 2),
+      extent: Vec2D.new(width - BLOCK_WIDTH, height - BLOCK_WIDTH)
+    )
+  end
+
+  def draw
+    background 0
+    fill 153
+    if block.over?(Vec2D.new(mouse_x, mouse_y))
+      @over_block = true
+      stroke 255
+      fill 255 if block_locked?
+    else
+      @over_block = false
+      stroke 153
+    end
+    # Draw the box as a shape
+    begin_shape
+    block.points_array.each { |vec| vec.to_vertex(renderer) }
+    end_shape(CLOSE)
+  end
+
+  def renderer
+    @renderer ||= AppRender.new(self)
+  end
+
+  def block_locked?
+    block_locked
+  end
+
+  def over_block?
+    over_block
+  end
+
+  def mouse_pressed
+    if over_block?
+      @block_locked = true
+      fill 255
+    else
+      @block_locked = false
+    end
+  end
+
+  def mouse_dragged
+    return unless block_locked?
+    position = Vec2D.new(mouse_x, mouse_y)
+    block.new_position(position) { bounds.contains? position }
+  end
+
+  def mouse_released
+    @block_locked = false
+  end
+
+  def settings
+    size 640, 360
+    smooth 4
+  end
+end
+AaBbExample.new
+
+# Use class to contain block behaviour
+class Block
+  attr_reader :aabb
+
+  def initialize(center:, size:)
+    @aabb = AaBb.new(center: center, extent: size)
+  end
+
+  def new_position(center, &block)
+    @aabb.position(center.dup, &block)
+  end
+
+  def over?(vec)
+    aabb.contains? vec
+  end
+
+  # use for shape
+  def points_array
+    a = aabb.center - aabb.extent * 0.5
+    c = aabb.center + aabb.extent * 0.5
+    b = Vec2D.new(c.x, a.y)
+    d = Vec2D.new(a.x, c.y)
+    [a, b, c, d]
+  end
+
+  # use for rect
+  def points
+    [aabb.center, aabb.extent]
+  end
+end

processing_app/library/vecmath/vec2d/acceleration_with_vectors.rb

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+#
+# Acceleration with Vectors 
+# by Daniel Shiffman.
+# PVector was used in the original (instead of Vec2D)
+# 
+# Demonstration of the basics of motion with vector.
+# A "Mover" object stores location, velocity, and acceleration as vectors
+# The motion is controlled by affecting the acceleration (in this case 
+# towards the mouse)
+#
+# For more examples of simulating motion and physics with vectors, see 
+# Simulate/ForcesWithVectors, Simulate/GravitationalAttraction3D
+#
+
+# A Mover object
+attr_reader :mover
+
+def setup
+  sketch_title 'Acceleration With Vectors'
+  @mover = Mover.new(width, height)
+end
+
+def draw
+  background(0)
+  # Update the location
+  mover.update
+  # Display the Mover
+  mover.display
+end
+
+####
+# The Mover class
+####
+
+class Mover	
+  # The Mover tracks location, velocity, and acceleration 
+  attr_reader :location, :velocity, :acceleration,
+  # The Mover's maximum speed
+  :topspeed
+  
+  def initialize(width, height)
+    # Start in the center
+    @location = Vec2D.new(width / 2, height / 2)
+    @velocity = Vec2D.new
+    @topspeed = 5
+  end
+  
+  def update    
+    # Compute a vector that points from location to mouse
+    mouse = Vec2D.new(mouse_x, mouse_y)
+    @acceleration = mouse - location
+    # Set magnitude of acceleration
+    acceleration.set_mag(0.2)    
+    # Velocity changes according to acceleration vector
+    @velocity += acceleration
+    # Limit the velocity to topspeed, PVector has a limit function 
+    # here we supply a block that evaluates to a boolean to set
+    # the velocit conditionally
+    velocity.set_mag(topspeed) { velocity.mag > topspeed }
+    # Location changes by velocity vector
+    @location += velocity
+  end
+  
+  def display
+    stroke(255)
+    stroke_weight(2)
+    fill(127)
+    ellipse(location.x, location.y, 48, 48)
+  end
+end
+
+def settings
+  size 640, 360, P2D
+end

processing_app/library/vecmath/vec2d/bouncing_ball.rb

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+require 'propane'
+#
+# Bouncing Ball with Vectors
+# by Daniel Shiffman.
+# PVector was used in the original (instead of Vec2D)
+#
+# Demonstration of using vectors to control motion of body
+# This example is not object-oriented
+# See AccelerationWithVectors for an example of how to simulate motion using vectors in an object
+class BouncingBalls < Propane::App
+  RADIUS = 24
+
+  attr_reader :loc,  # Location of shape
+  :velocity,  # Velocity of shape
+  :gravity   # Gravity acts at the shape's acceleration
+
+  def setup
+    sketch_title 'Bouncing Ball'
+    @loc = Vec2D.new(100, 100)
+    @velocity = Vec2D.new(1.5, 2.1)
+    @gravity = Vec2D.new(0, 0.2)
+  end
+
+  def draw
+    background(0)
+    # Add velocity to the location.
+    @loc += velocity
+    # Add gravity to velocity
+    @velocity += gravity
+    # Bounce off edges
+    velocity.x *= -1 unless (RADIUS..width - RADIUS).include?(loc.x)
+    if loc.y > (height - RADIUS)
+      # We're reducing velocity ever so slightly
+      # when it hits the bottom of the window
+      velocity.y *= -0.95
+      loc.y = height - RADIUS
+    end
+    # Display circle at location vector
+    stroke(255)
+    stroke_weight(2)
+    fill(127)
+    ellipse(loc.x, loc.y, RADIUS * 2, RADIUS * 2)
+  end
+
+  def settings
+    size(640, 360)
+    smooth 4
+  end
+end
+
+BouncingBalls.new